1. Field of the Invention
The present invention relates to a set of rotor disks for a turbine engine such as an airplane turboprop or turbojet.
2. Description of the Related Art
In a conventional turbine engine, as described in document EP 2 009 235 in the name of the Applicant, the rotor of the turbine comprises a plurality of disks with slots formed in their peripheries for receiving blade roots. The disks are centered on the axis of the engine and they are connected together and to a turbine shaft by upstream and downstream flanges, the downstream flange of an upstream disk being fastened to the upstream flange of a downstream disk by means of bolts.
An annular holder plate for holding blade roots is fastened to the upstream flange of the downstream disk and extends over the slots of the disk so as to form an axial abutment for the blade roots mounted in the disk.
This plate also carries wipers for co-operating with blocks of abradable material mounted on stationary vanes of a guide vane stage situated axially between the two above-mentioned disks, one upstream and the other downstream. The wipers and the abradable blocks form sealing means of the labyrinth seal type.
An annular space is defined between the plate and the upstream flange of the downstream disk and it is fed upstream with air that is guided to the slots of the downstream disk in order to cool them.
The disks are machined from respective raw forgings that present axial dimensions that are considerable, as required for forming the flanges that extend upstream and downstream. The machining time and the cost that result therefrom are very great.
In order to limit manufacturing costs, it is known to use disks having a radial rim that does not have any axial flanges. Two disks of that type are then connected together by means of a disk of another type that is interposed axially between them, which disk of the other type has upstream and downstream flanges of great length. Although the amount of machining required for the disks that do not have any flanges is greatly reduced, the machining required for the intermediate disks having flanges remains very great.
The ferrules carrying the wipers also need to be redefined, given the structural modifications made to the disks.